The following CVS commit on Feb 10th, of CHANGELOG entry 864 has broken
VTswitching between VTs while switched away from the X server:
865. Add private keysyms for the new XKB actions (XFree86 special keys),
and move those actions to an XKB compatibility map. This fixes
side-effects (loss of auto-repeat and mousekeys functionality) of
the way this was implemented previously (#5610, Ivan Pascal).
To reproduce:
1) Install XFree86 release from Feb 10th or later that has #865
2) startx
3) Switch away to any other VC with CTRL-ALT-Fn
4) Try to switch to another VC now other than the one the X
server is running on.
Results:
The console switches only for a very short flash to the requested
console, then switches back. You are effectively stuck on the
tty you've switched to, and can only switch back to the X server
itself.
Other info:
While switched away from the X server, if you kill the server,
then VT switching works again.
I have backed out the changes from that one commit, and the
problem is gone in build 20030212.0.

Oops, I mean it was reverted with XFree86-4.2.99.901-revert-xkb-patch-865.patch
in 20030211.3 and later.
The latest CVS snapshot applies a correct fix for this problem, so
I have removed the above patch, and this problem should be fixed
in build: XFree86-4.2.99.901-20030213.0
Setting bug to MODIFIED pending testing.